Dental implant, bone graft and sinus lift for upper left molar - questions for people with experience., what to do?

Same procedure. I had a surgical extraction and bone graft for an upper left molar on myself last week. Membrane will be removed next week. Very little discomfort and took no pain meds.
What to do? Without personally examining you and your x-rays we can't advise you what to do or not to do. What you describe is state of the art dentistry and something i would do in my own mouth if needed. You must find a dentist whom you trust and follow his\her advice after discussing treatment alternatives and prognosis of each. If necessary seek 2nd or 3rd opinion until you feel confident in your decision.
Do it ! If the adjacent teeth do not needs crowns or already have crowns, then the above procedure is the best bet for you. Cutting down healthy teeth to support a bridge is not longer needed with the grafting techniques available. Hope this is what you were asking..